Grinding machine



July 9, 1929. PQBRUHL 1,719,965

GRINDING mciunn v 7 Filed Sept. 30, 1927 3 Sheets-Sheet 1 i I v I n y 9, 1929- P. BRUHL GRINDING MACHINE Filed Sept. 30, 1927 3 Sheets-Sheet 2 4 {I n. J

July 9, 1929. r P. BRUHL 1,719,965

GRINDING MACHINE Patented July 9, 1929.

UNITED STATES PAUL nnt'rnt, or DUSSELDORF, GERMANY;

GRINDING MACHINE.

Application filed September 30, 1927, Serial No. 223,134, and in Germany October 12, 1926.

My invention relates to grinding machines in which the blanks, rollers or balls, are suctessively fed through a passage or passages defined in a pair of grinding plates.

It is an object of my invention to prevent deformation and unequal wear of the blanks and the passages, and for this purpose I separate the grinding plates before inserting the blanks in the passage or passages.

In the existing grinding machines of this type, it has been found that when rollers are groundtheir ends are rounded and they are made with a depression at the centre, and

the ends of the passages are flared bythe entrance of the blanks, rollers or balls. This is ,due to the fact that the blanks will-knock against the edges of the grinding plates when entering a passage so that they'will not only wear the passages as mentioned but also will assume an irregular position with respect to the passage sothat they will move along the passage with their axis at an angle to the longitudinal axis of the passage.

This drawback is overcome in my inven tion by separating the grinding plates for the reception of the blanks, the plates being moved so far apart in vertical direction .with respect to their faces that the blanks can be inserted-properly aligned and at the same time shocks and undue friction are eliminated. The grinding plates are brought together preferably after the blanks have advanced so far within the passages that they will be in parallel position. I might separate the plates by moving both of them and I am not limited to displacing but a single plate while the other remains in position but this is preferred. By means of a suitable system of links and levers, or other mechanism, the movable plate is raised from the other plate when a blank is being inserted, and is held raised until the blank has been completely inserted, or, at least, until the blank has entered the passage to such an extent thatit will be aligned by the plates during their closing movement.

In a preferred embodiment of my invention I so arrange the guide by which the blanks are fed to the passage that it is at a.

slightly higher level than the passage in the lower grinding plate so that when a blank is moved into the passage from the guide it cannot strike the edge of the plate in the vicinity of the passage.

My invention may be applied to grinding machines having a single passage as well as to machines having any number ofpassages in thelr grinding plates, care being taken that 1n the latter case all blanks will enter the respective passages at the same time.

I may also provide means for causing relative displacement of the grinding plates in the direction of the grinding passages in a straight line or on a slightly curved path, according to whether the rollers are ground parallel, convex or concave.

In the accompanying drawings a machine embodying my invention is illustrated, by way of example.

Fig. 1 is an elevation, partly in section, of the machine.

Figs. 2 and 3 are part cross sections showmg the grinding plates separated and united, respectively.

Figs. 4 and 5 are plan views of the machine, the upper or movable grinding plate being removed, with the parts in two positions.

F g. 6 is a part sectional elevation, illustrating the application of modified feeding means for the blanks.

Figs. 7 and 8 are cross sections of the grinding plates taken through line VIII VIII of Fig. 6 and show the upper grinding plate in raised and lowered positions respectively.

Referring particularly to Figs. 1 to 5, each of grinding plates 7 and 8 has six grooves and when the plates are brought together the grooves of one plate register with those of the other to form the passages 1 to 6. The lower plate 7 is mounted on a frame 7. Reoiprocation is imparted to frame 7 and thereby to plate 7, as indicated by the arrow, 9, by means of a rocking arm 7 engaging frame 7 and a crank 7 to which rotation is imparted by suitable means not shown. On

and 29 at a slightly higher level than the bases of the passages 1 to 6. This diflerence is so slight that it oann'otbe shown in true scale in the drawing and is therefore greatly exaggerated.

10 is a bracket in which the upper grinding plate 8 is carried, 11 is an upright connected with the machine frame on which the bracket is guided, 18 is a shaft to which rotationis imparted from the driving shaft of the machine, not shown, 19 is a cam on the shaft 18, 20 is a rocking arm fulcrumed on the upright 11, 21 is a connecting rod, and 22 is a lever which is fulcrumed at 24 and with its inner end 23 engages "a slot 24' in the bracket 10.

either side of the plate 7 extend shelves 28 By these means the bracket is reciprocated as indicated by the arrow 12.

.A push bar is allotted to each of the pas sages 1 to 6, and the six push bars are divided into two groups 14 and 15 secured'to cross heads 14 and 15, respectively. Reciproca-, tion is imparted to'the cross heads and thereby to the push bars, as indicated by arrow 16, by means of rocking arms 17 fulcrumed in the frame of the machine and cranks 17 to which rotation is imparted by suitable means not shown. 1

best seen in Figs. 4 and 5, each of the push bars 14 and 15, upon entering the passages in the grinding plates, moves a blank into the mssageallotted to it and at the same time feeds the row of blanks in advance of the firstblank until a blank is discharged at the o )osite end of the )tlSSR P. Means enorally indicated at-l l and 15" at either end of the grinding plates, but not shown in detail as they-form no part of the present invention, are provided "for moving the discharged blanks into the-.path of an adjacent push rod whichpushes the blanks into the passage to which the rod is allotted. This cycle of operations is'repeated until all blanks have been moved through the passages on a serpentine path, and any number of cycles is performed until the blanks 'have been finished.

The operation of the push bars and the bracket 10 are so timed that the upper grinding plate 8 is raised when the push bars start to push a. blank into the passages, and islow' ered when the blank has been completely or partly moved mto the corresponding passage.

Means may be provided for permanently raising the upper grinding plate, if desired,

for instance, when removing a finished lot of blanks, and such means may comprise a screw spindle 25 in a threadedsleeve 26 which is rotatably carried but held against axial displacement. The sleeve is equipped with a helical pinion at its upper end with which meshes with a pinion 27 on the shaft of a hand wheel 33. The upper end of the spindle 25 1s splined at 34 and provided-with a stop plate 35 to limit its downward movement.

lVhen it is desired to.-hold the bracket 10 in a stationary position the spindle. 25 is actuated by means of the hand wheel until it engages the top of'the upright 11 with its stop 35. Upon further actuation of the spindle the bracket 10 is raised beyond reach of the arm arm upon actuation of the spindle 25 in opposite direction.

.In operation, when blanks 13 are ready to enter the passages I to 6, the cam 19 will be in the position indicated in Fig. 2 in which the upper plate '8 is raised from the lower plate "7 so that the blanks can be properly and readily inserted. After the blanks have entered the respective passages they are held in position and guided by the passages, and

.of a passa e,

23, and is placed within reach of. said the upper bracket 10 upon being lowered with plate 8 comes upon the blanks in correct position, as shown in Fig. 3. Then the blanks are fed through .the passages and ground and finally are discharged as described. The lowering of the bracket may be under the action of gravity or suitable springs.

Referring now to Figs. 6, 7, and 8, identical parts have been marked with the same reference numerals as in the preceding figures, andin this instance instead of push bars, a combined belt and cage 30 is provided which is endless and moves intermittently or continuously, taking the blanks through any number of passages 31, 32. The shelves 28', 2. are here slightly higher than the bases of the grinding passages, as described with reference to Figs. 1 to 5, and means similar to those described, or of other construction, are provided for raising the upper plate 8 at the proper time with relation to the operation of the belt and cage 30, as shown in Fig. 7 The belt and cage 30 may be carried on sprockets, not shown, to which reciprocating movement is imparted by a ratchet mechanism.

I claim:

l. A grinding machine comprising a pair of grinding plates, each plate defining a part of a passage, means for feeding blanks through said passage, and means for separating, and bringing together said plates.

'2. A grinding machine com rising a pair of grinding plates, each plate efining a part of a passage, means for feeding blanks through said passage, and means for alternately separating and bringing together said plates in time with the operation of said rating said plates before said feeding means act to insert a blank in said passage, and for has een inserted.

4. A grinding machine comfprising a'pair of grinding plates, each plate means for feeding blanks through sai passage, means for separating and bringing together said plates, and means for rendering inoperative said last-named means.

5. A grinding machine comprisingv a frame, a pair of grinding plates on'said frame, each plate defining av part of a passage, means for feeding blanks throu b said passage, a bracket to which one of saiifplates is secured, means for imparting a reciproeating motion to said bracket, a screw spindle non-rotatably mounted on said frame, a threaded sleeve for said spindle mounted on bringing together said. plates after the blank efining a part ,ment with respect to the latter, and means for rotating said sleeve so as to move said bracket into and out of engagement with said reciprocating means. a

6. A grinifling machine comprising upper and lower grinding plates, eaeh defining part of a passage, a guide from which blanks are fed to the passage, said guide being at a slightly higher level than the part of the pas- 10 sage defined in said lower grindingplate, means for feeding blanks from said guide to and through said passage, and means for alternately separating and bringing together saidplates in time with the operation of said 1 feeding means. 7

In testimony whereof I aflix my signature.

PAUL 'BRUHL. 

